EPA Greenlights Mississippi's SO2 Air Plan Update
Published Date: 8/27/2026
Proposed Rule
Summary
Pursuant to the Federal Clean Air Act (CAA or the Act), the U.S. Environmental Protection Agency (EPA or Agency) is proposing to approve a State Implementation Plan (SIP) revision submitted by the State of Mississippi, through the Mississippi Department of Environmental Quality (MDEQ), on January 27, 2022, for the purpose of complying with the "good neighbor" provision of the CAA for the 2010 1-hour sulfur dioxide (SO<INF>2</INF>) primary National Ambient Air Quality Standard (NAAQS). The good neighbor provision requires each State's implementation plan to contain adequate provisions prohibiting the interstate transport of air pollution in amounts that will contribute significantly to nonattainment, or interfere with maintenance, of a NAAQS in any other State. In this proposed rulemaking, the EPA is proposing to determine that Mississippi will not contribute significantly to nonattainment or interfere with maintenance of the 2010 1-hour SO<INF>2</INF> primary NAAQS in any other State. Therefore, the EPA is proposing to approve the January 27, 2022, SIP revision as meeting the requirements of the good neighbor provision for the 2010 1-hour SO<INF>2</INF> primary NAAQS.
Analyzed Economic Effects
1 provisions identified: 1 benefits, 0 costs, 0 mixed.
EPA Proposes Approval of Mississippi SO2 SIP
If you live in Mississippi, Alabama, Tennessee, or Louisiana, the EPA is proposing to approve Mississippi's State Implementation Plan (submitted January 27, 2022) for the 2010 1-hour sulfur dioxide (SO2) standard (75 parts per billion). The EPA's proposal says Mississippi will not significantly contribute to nonattainment or interfere with maintenance of the 2010 1-hour SO2 NAAQS in any other State, based on analyses that focused on sources within 50 kilometers of the State border and sources emitting over 100 tons per year. The Federal Register publication is August 27, 2026 and comments are due September 17, 2026.
Personalized for You
How does this regulation affect your finances?
Personalize government policy and PRIA will tell you what this federal register document means for your household, plus every other regulation we track. PRIA reads each provision against your financial profile to show you exactly what matters to your wallet.
Key Dates
Department and Agencies
Related Federal Register Documents
2026-14112, Amendments and Nonconformance Penalties for Model Year 2027 and Later Heavy-Duty Highway Engines and Amendments to Inducement Provisions for SCR-Equipped Diesel Engines
Starting with model year 2027, the EPA is updating rules for big truck engines to make sure they last longer and pollute less. They’re also letting engine makers pay penalties if their engines don’t meet standards, and tightening rules for special pollution-control systems on diesel engines. These changes affect truck and engine makers and kick in soon, with public feedback due by August 29, 2026.
2026-13667, Minor New Source Review Program Air Permitting Public Participation Requirements for State Implementation Plans
The EPA wants to give states more freedom to decide how much public input is needed when approving small air pollution sources or changes. This means local air agencies can tailor public participation to fit their community’s needs while still protecting air quality. If you’re involved in air permits, watch for comment deadlines and possible virtual hearings this summer!
2026-13263, Revisions To Establish the Sixth Unregulated Contaminant Monitoring Rule (UCMR 6) for Public Water Systems
The EPA is rolling out the sixth Unregulated Contaminant Monitoring Rule (UCMR 6) to check for new, sneaky chemicals in public drinking water. Big water systems serving 3,300+ people and some smaller ones will test for 30 different contaminants, including certain PFAS and pesticides, to keep our water safe. Comments and feedback are open until late August 2026, and the EPA will host fun online meetings to chat about the plan!
2026-12927, U.S. Ecology Nevada, Inc. High Mercury Subcategory Wastes Land Disposal Restrictions Variance
The EPA is giving U.S. Ecology Nevada a special green light to handle and dispose of high-mercury waste a bit differently than usual. This means mercury waste treated in Pennsylvania can now be safely sent to U.S. Ecology’s Nevada site for disposal under new rules starting July 27, 2026. This change helps protect people and the environment while keeping mercury waste management efficient and cost-effective.
2026-11047, National Emission Standards for Hazardous Air Pollutants From Hazardous Waste Combustors: Residual Risk and Technology Review
The EPA just updated rules for places that burn hazardous waste, like incinerators and boilers, to keep the air safe and clean. They confirmed current standards work well but added new limits on harmful gases like hydrogen fluoride and hydrogen cyanide. These changes start June 3, 2026, and include easier electronic reporting and some new rules for startup and shutdown times—helping protect health without big costs.
2026-10641, Hazardous and Solid Waste Management System: Disposal of Coal Combustion Residuals From Electric Utilities; Federal CCR Permit Program; Reopening of Comment Period
The EPA is reopening the comment period until June 29, 2026, for its proposed rule to create a federal permit program for safely disposing of coal ash from power plants. This affects electric utilities that handle coal waste and aims to improve environmental safety while possibly impacting their costs. Now’s the time for everyone to share their thoughts and help shape the rules!
Previous / Next Documents
Previous: 2026-17502, Air Plan Approval; Kentucky; Cincinnati-Hamilton Area Limited Maintenance Plan for the 1997 8-Hour Ozone NAAQS
The U.S. Environmental Protection Agency (EPA or Agency) is proposing to approve a State Implementation Plan (SIP) revision submitted by the Commonwealth of Kentucky through the Energy and Environment Cabinet (Cabinet), Division of Air Quality (Division), on July 23, 2024. The SIP revision consists of a Limited Maintenance Plan (LMP) for the Kentucky portion of the tri-state Cincinnati-Hamilton 1997 8-hour ozone nonattainment area (the "tri-state Cincinnati-Hamilton Area"). The Kentucky portion of the tri-state Cincinnati-Hamilton Area is composed of Boone, Campbell, and Kenton Counties in Kentucky (hereinafter also referred to as the "Northern Kentucky Area"). The EPA is proposing to approve Kentucky's LMP for the Northern Kentucky Area because it provides for the maintenance of the 1997 8-hour ozone National Ambient Air Quality Standards (NAAQS) within the tri-state Cincinnati-Hamilton Area through the end of the second 10-year portion of the maintenance period. The effect of this proposed action would be to make certain commitments related to maintenance of the 1997 8-hour ozone NAAQS in the Northern Kentucky Area federally enforceable as part of the Kentucky SIP.
Next: 2026-17504, Agency Information Collection Activities; Submission to the Office of Management and Budget for Review and Approval; Comment Request; Performance Evaluation Studies on Wastewater Laboratories (Renewal)
The Environmental Protection Agency (EPA) has submitted an information collection request (ICR), Performance Evaluation Studies on Wastewater Laboratories (EPA ICR Number 0234.15, OMB Control Number 2080-0021) to the Office of Management and Budget (OMB) for review and approval in accordance with the Paperwork Reduction Act. This is a proposed extension of the ICR, which is currently approved through August 31, 2026. Public comments were previously requested via the Federal Register on May 21, 2026 during a 60-day comment period. This notice allows for an additional 30 days for public comments.